#include <iostream>

long cal(long start, long end)
{
	long res = 0;
	
	for(int i = start; i <= end; i++)
	{
		res += i;
	}
	
	return res;
}

int main()
{
	long start;
	long end;
	
	std::cout << "Enter start number and end number (type is long): "; std::cin >> start >> end;
	std::cout << "The sum range from start and end is: " << cal(start, end) << "\n";
	
	return 0;
}
